Tanga offers the Dream Home 6-Piece Double-Brushed Microfiber Sheet Set in eight colors (Ivory pictured) for $13.99 plus $4.99 for shipping. That's $86 off list and the lowest total price we could find. They're available in sizes Full and Queen. Each set includes four pillowcases, one fitted sheet, and one flat sheet.
Of note, this set is also available in King for $14.99 plus $4.99 for shipping.